Tolerances and resultant fits

The tables in this section provide information about bearing tolerances, seat tolerances and resultant fits (fig. 1). These should enable you to determine easily the maximum and minimum values of fits when using ISO tolerance classes for bearing seats and bearings with Normal tolerances for the bore and outside diameter. The SKF Bearing Calculator provides a similar function for every individual bearing.

The tables cannot be used for tapered roller bearings when d ≤ 30 mm or D ≤ 150 mm or thrust bearings when D ≤ 150 mm. The diameter tolerances for these bearings deviate from the Normal tolerances for other rolling bearings.

The tables list:

the upper and lower limits of bore or outside diameter deviations for bearings with Normal tolerances

the upper and lower limits of shaft or housing bore diameter deviations for relevant tolerance classes in accordance with ISO 286­2

the smallest and largest values of the theoretical interference (–) or clearance (+)

the smallest and largest values of the ±3σ probable interference (–) or clearance (+)

The appropriate values for shaft seats are listed for the following tolerance classes: